1. Field of the Invention
The present invention relates to devices for the delivery of pharmaceuticals, and particularly to a bioinjection device for delivering bone morphogenic protein, antibiotics, etc., directly to the site of a bone fracture, degenerative bone tissue or cartilage, etc., during the course of surgery in the form of a bioabsorbable matrix enclosed within a membrane cartridge.
2. Description of the Related Art
Bone is a living tissue and plays a structural role in the body. Disease and damage, however, is often difficult to treat in bones, due to their positioning within the soft tissues of the body. Bone consists of repeating Harvesian systems (concentric layers of lamellae deposited around a central canal containing blood vessels and nerves). The central canal is also known as the medullary cavity and is filled with bone marrow. Within the shaft of a long bone, many of these Harvesian systems are bundled together in parallel, forming a type of bone called compact bone, which is optimized to handle compressive and bending forces. In some bones, such as the metacarpals, for example, the bones themselves are hollow and contain little, if any, marrow. Near the ends of the bones, where the stresses become more complex, the Harvesian systems splay out and branch to form a meshwork of cancellous or spongy bone. Compact bone and cancellous bone differ in density, or how tightly the tissue is packed together.
Genetic or developmental irregularities, trauma, chronic stress, tumors, and disease can result in pathologies of bones. Some bone diseases that weaken the bones include, but are not limited to, osteoporosis, achondroplasia, bone cancer, fibrodysplasia ossificans progressiva, fibrous dysplasia, legg calve perthes disease, myeloma, osteogenesis imperfecta, osteomyelitis, osteopenia, osteoporosis, Paget's disease, and scoliosis. Weakened bones are more susceptible to fracture, and treatment to prevent bone fractures becomes important. Severe fractures, such as those that are open, multiple, or to the hip or back, are typically treated in a hospital. Surgery may be necessary when a fracture is open, severe, or has resulted in severe injury to the surrounding tissues. Severe fractures may require internal devices, such as screws, rods, or plates, to hold the bone in place or replace lost bone during the healing process.
In order to repair severe fractures, bone cement and the like is often applied within the fracture. However, other healing agents, such as antibiotics or bone morphogenic proteins, often need to be applied prior to cementing or performance of other operations on the bone. Due to the awkward positioning of bone fractures within other tissue, it is often quite difficult to properly apply medicaments and the like within the bone, particularly without damaging the tissue surrounding the bone. Thus, a bioinjection solving the aforementioned problems is desired.